During ancient times the lands now comprising Iraq were known as Mesopotamia (“Land Between the Rivers”), a region whose extensive alluvial plains gave rise to some of the world’s earliest civilizations, including those of Sumer, Akkad, Babylon, and Assyria. This wealthy region, constituting much of what is called the Fertile Crescent, later became a valuable part of larger imperial polities, including sundry Persian, Greek, and Roman dynasties, and after the 7th century became a central and integral part of the Islamic world. Iraq’s capital, Baghdad, became the capital of the ʿAbbāsid Caliphate in the 8th century. The modern nation-state of Iraq was created following World War I (1914–18) from the Ottoman provinces of Baghdad, Al-Baṣrah, and Mosul and derives its name from the Arabic term used in the premodern period to describe a region that roughly corresponded to Mesopotamia (ʿIrāq ʿArabī, “Arabian Iraq”) and modern northwestern Iran (ʿIrāq ʿajamī, “foreign [i.e., Persian] Iraq”).

Iraq gained formal independence in 1932 but remained subject to British imperial influence during the next quarter century of turbulent monarchical rule. Political instability on an even greater scale followed the overthrow of the monarchy in 1958, but the installation of an Arab nationalist and socialist regime—the Baʿth Party—in a bloodless coup 10 years later brought new stability. With proven oil reserves second in the world only to those of Saudi Arabia, the regime was able to finance ambitious projects and development plans throughout the 1970s and to build one of the largest and best-equipped armed forces in the Arab world. The party’s leadership, however, was quickly assumed by Ṣaddām Ḥussein, a flamboyant and ruthless autocrat who led the country into disastrous military adventures—the Iran-Iraq War (1980–88) and the Persian Gulf War (1990–91). These conflicts left the country isolated from the international community and financially and socially drained, but through unprecedented coercion directed at major sections of the population—particularly the country’s disfranchised Kurdish minority and Shīʿite majority—Ṣaddām himself was able to maintain a firm hold on power into the 21st century. He and his regime were toppled in 2003 during the Iraq War.

Land

Iraq is one of the easternmost countries of the Arab world, located at about the same latitude as the southern United States. It is bordered to the north by Turkey, to the east by Iran, to the west by Syria and Jordan, and to the south by Saudi Arabia and Kuwait. Iraq has 12 miles (19 km) of coastline along the northern end of the Persian Gulf, giving it a tiny sliver of territorial sea. Followed by Jordan, it is thus the Middle Eastern state with the least access to the sea and offshore sovereignty.

Relief

Middle East: IraqEncyclopædia Britannica, Inc.Iraq’s topography can be divided into four physiographic regions: the alluvial plains of the central and southeastern parts of the country; Al-Jazīrah (Arabic: “the Island”), an upland region in the north between the Tigris and Euphrates rivers; deserts in the west and south; and the highlands in the northeast. Each of these regions extends into neighbouring countries, although the alluvial plains lie largely within Iraq.

ʿArab, Shaṭṭ Al-Diane Rawson/Photo ResearchersThe plains of lower Mesopotamia extend southward some 375 miles (600 km) from Balad on the Tigris and Al-Ramādī on the Euphrates to the Persian Gulf. They cover more than 51,000 square miles (132,000 square km), almost one-third of the country’s area, and are characterized by low elevation, below 300 feet (100 metres), and poor natural drainage. Large areas are subject to widespread seasonal flooding, and there are extensive marshlands, some of which dry up in the summer to become salty wastelands. Near Al-Qurnah, where the Tigris and Euphrates converge to form the Shatt al-Arab, there are still some inhabited marshes. The alluvial plains contain extensive lakes. The swampy Lake Al-Ḥammār (Hawr al-Ḥammār) extends 70 miles (110 km) from Al-Baṣrah (Basra) to Sūq al-Shuyūkh; its width varies from 8 to 15 miles (13 to 25 km).

Deserts

Western and southern Iraq is a vast desert region covering some 64,900 square miles (168,000 square km), almost two-fifths of the country. The western desert, an extension of the Syrian Desert, rises to elevations above 1,600 feet (490 metres). The southern desert is known as Al-Ḥajarah in the western part and as Al-Dibdibah in the east. Al-Ḥajarah has a complex topography of rocky desert, wadis, ridges, and depressions. Al-Dibdibah is a more sandy region with a covering of scrub vegetation. Elevation in the southern desert averages between 300 and 1,200 feet (100 to 400 metres). A height of 3,119 feet (951 metres) is reached at Mount ʿUnayzah (ʿUnāzah) at the intersection of the borders of Jordan, Iraq, and Saudi Arabia. The deep Wadi Al-Bāṭin runs 45 miles (75 km) in a northeast-southwest direction through Al-Dibdibah. It has been recognized since 1913 as the boundary between western Kuwait and Iraq.

The northeast

The mountains, hills, and plains of northeastern Iraq occupy some 35,500 square miles (92,000 square km), about one-fifth of the country. Of this area only about one-fourth is mountainous; the remainder is a complex transition zone between mountain and lowland. The ancient kingdom of Assyria was located in this area. North and northeast of the Assyrian plains and foothills is Kurdistan, a mountainous region that extends into Turkey and Iran.

The relief of northeastern Iraq rises from the Tigris toward the Turkish and Iranian borders in a series of rolling plateaus, river basins, and hills until the high mountain ridges of Iraqi Kurdistan, associated with the Taurus and Zagros mountains, are reached. These mountains are aligned northwest to southeast and are separated by river basins where human settlement is possible. The mountain summits have an average elevation of about 8,000 feet (2,400 metres), rising to 10,000–11,000 feet (3,000–3,300 metres) in places. There, along the Iran-Iraq border, is the country’s highest point, Ghundah Zhur, which reaches 11,834 feet (3,607 metres). The region is heavily dissected by numerous tributaries of the Tigris, notably the Great and LittleZab rivers and the Diyālā and ʿUẓaym (Adhaim) rivers. These streams weave tortuously south and southwest, cutting through ridges in a number of gorges, notably the Rū Kuchūk gorge, northeast of Barzān, and the Bēkma gorge, west of Rawāndūz town. The highest mountain ridges contain the only forestland in Iraq.

Drainage

Tigris RiverRobert Harding Picture Library/SuperStockIraq is drained by the Tigris-Euphrates river system, although less than half of the Tigris-Euphrates basin lies in the country. Both rivers rise in the Armenian highlands of Turkey, where they are fed by melting winter snow. The Tigris flows 881 miles (1,417 km) and the Euphrates 753 miles (1,212 km) through Iraq before they join near Al-Qurnah to form the Shatt al-Arab, which flows another 68 miles (109 km) into the Persian Gulf. The Tigris, all of whose tributaries are on its left (east) bank, runs close to the high Zagros Mountains, from which it receives a number of important tributaries, notably the Great Zab, the Little Zab, and the Diyālā. As a result, the Tigris can be subject to devastating floods, as evidenced by the many old channels left when the river carved out a new course. The period of maximum flow of the Tigris is from March to May, when more than two-fifths of the annual total discharge may be received. The Euphrates, whose flow is roughly 50 percent greater than that of the Tigris, receives no large tributaries in Iraq.

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